Product expiration date (good within 12 months after opening)

[Monique]

I have a spray sun protector, on it is a date that the product is good until 12 months after opening. However, there is no shelf date. Since it's a spray it has not been in contact with the outside environment, so why would it spoil?

Should I continue using it? In other words, should I not accept the product claim that it expires 12 months after opening?

I can exchange it for a cheap brand for 70% off, but it feels like a waste to throw the bottle away.

 

[jedishrfu]

It's possible that the chemicals could degrade ven if you don't open it and its more possible that the air can assist in degrading it more.

Not knowing the answer, the question becomes do you want to risk getting a sunburn from using an old and out of date product.

 

[Danger]

A consumer report that just showed up here a week or so ago on the news showed that most sun-block products are not nearly as effective as they claim to be, so I doubt that a "best by..." date makes a huge difference.
I agree, though, that it doesn't have to be open to degrade. Air might not be specifically excluded from the can, even if the propellant is an inert gas.
You could just drape some fabric over your tender bits while tanning.

 

[Greg Bernhardt]

This is an interesting debate with medications.
http://www.health.harvard.edu/fhg/updates/update1103a.shtml

Usually I consider expiration dates on most things to be a business tactic and am flexible with it depending on the product.

 

[Monique]

You could just drape some fabric over your tender bits while tanning.

Do you realize how awkward that comment is?

This is an interesting debate with medications.
http://www.health.harvard.edu/fhg/updates/update1103a.shtml

Usually I consider expiration dates on most things to be a business tactic and am flexible with it depending on the product.

I've decided that the expiration date is probably more a theoretical than practical one, the bottle was hardly used anyway. I did exchange two (expensive) sun products that were probably over three years old for two new ones of the cheap brand, I ended up paying a little over a Euro for an €18 purchase: a good deal.

Now the only thing missing is some good weather to test them.

 

[Danger]

Do you realize how awkward that comment is?

You do know who I am, right? Of course I realize it; that's why I wrote it. (Although I would use the term "suggestive" since it wasn't the least bit awkward for me.)

 

[Monique]

Well, I'd appreciate it if you would refrain from the suggestive remarks. They're awkward, there are already enough people in real life who think that making suggestive or even explicit remarks is appropriate, which it is not.

 

[Bacle2]

The response by some companies in the US was that the expiration date given is that of the person consuming the product :) .

 

[Danger]

Well, I'd appreciate it if you would refrain from the suggestive remarks. They're awkward, there are already enough people in real life who think that making suggestive or even explicit remarks is appropriate, which it is not.

Actually, the facetious part of my response was saying that I knew it was suggestive. It honestly never occurred to me that a casual reference to nude sunbathing could offend anyone, particularly a European. As I understand it, all beaches in the Netherlands are topless, and many clothing-optional. It just seemed like an innocuous joke. I apologize.

 

[fluidistic]

I've had a really bad experience by applying a skin lotion (sun's after burn) that was expired by far. A few hours after I applied it on my whole body, I begun to feel terribly itchy. I could not stop to scratch myself everywhere, when I stopped for a few seconds I would feel like vomiting. I went to a doctor while scracting myself like crazy but then the itchiness disappeared right when he was about to inject me some product.
From that day and on, I took more care about experiration dates for skin products.
In my case it wasn't a spray but just in case, I would not use a product that has expired.

 

[Danger]

I've had a really bad experience

That sounds like a histamine reaction. Is it possible that you're just allergic to the product, or had you used a fresh version previously with no ill effect?

 

[FlexGunship]

Usually I consider expiration dates on most things to be a business tactic and am flexible with it depending on the product.

Meat, bread, fruit, vegetables, and dairy. Everything else is fair game.

I just tested some tortilla chips last night. They "expired" six months ago. The experiment was a failure: I was never able to ascertain how unfit for consumption they were because I couldn't even consume them. I'd recommend them as building material, however.

Specifically, sunblock with zinc oxide (which I think it the most common) is good until prolonged exposure to moisture... but even that I think only pertains to when it's applied and not in storage. Honestly, I don't know.

Buy a brand new bottle. Then you could try it on one part of your body, and compare it to a control group else where on your body. I don't know how you'd achieve double-blind status in this test without someone applying it for you, though. Or maybe putting some of each into shot glasses labeled "A" and "B". Hmm... do you have an assistant to help?

EDIT: Actually, I'm 100% sure I have a bottle of sunblock around that's older than a year. I'll run this test as soon as I get a chance.

DOUBLE EDIT: Is the visible color of skin (i.e. tanned/sunburned/unchanged) a good indicator of efficacy in this case?